Silicon (orthosilicic acid)

Tier 2 — promising · Bone · Hair thickness · Nails

The third most abundant trace element in the body, involved in collagen cross-linking, bone mineralisation, and connective tissue strength. Liquid orthosilicic acid is the only form with demonstrated bloodstream absorption. A 2024 trial found 10 mg/day significantly increased hair thickness and reduced nail brittleness after 20 weeks.

Dose: 5–10 mg/day orthosilicic acid in liquid form; solid silica supplements are poorly absorbed